A clampdown on South Australia's vaping industry has drawn fire from advocates who consider it a "perverse" reaction to ideological attitudes that will cost jobs and leave addicts little choice but to revert to smoking.

The state is the frontline of a debate that will continue for some time, as policy makers weigh any benefits for vapers who switch from smoking and the potential to reduce smoking rates, against inadequate knowledge about the risks of e-cigarettes themselves.

South Australia will also prohibit people within its borders from making online e-cigarette purchases from interstate or overseas, with enforcement officers to monitor and prosecute anyone selling into SA in line with the existing online tobacco ban.

But vape stores in Australia do not sell tobacco or nicotine products and are restricted to devices and flavouring alone.

Customers who want nicotine must order it in liquid form from overseas and add it to their devices themselves.

Liquid nicotine considered a poison

The Therapeutic Goods Administration (TGA) has rejected renewed calls to allow liquid nicotine to be regulated for e-cigarettes and labelled for sale from inside Australia.

The TGA insists it is a poison — unless packed in tobacco prepared for smoking, labelled and packed for the treatment of animals, or prepared for approved methods of human therapeutic use — and cited concerns about the attractiveness of vaping to young people.

"Current government policy supports the cessation of smoking rather than harm reduction," it stated.

Earlier this year, the British government agency Public Health England (PHE) said evidence there did not support concerns that e-cigarettes were a route into smoking among young people, and that vaping was confined almost entirely to those who have smoked already.

It said it was more concerned that misinformation about e-cigarettes had led 40 per cent of smokers to incorrectly believe vaping was just as harmful as smoking.

"Vaping poses only a small fraction of the risks of smoking and switching completely from smoking to vaping conveys substantial health benefits," it said.

"E-cigarettes could be contributing to at least 20,000 successful new quits per year and possibly more."

Switching to vape as last resort

Peter and Lianne from Meadows were pack-a-day smokers who could not quit despite trying everything, from nicotine gum to patches and nicotine-replacement therapies.

They made a choice to switch to vaping three-and-a-half years ago and have not touched a cigarette since.

"Within a couple of weeks, the coughing stopped and I can walk up hills and do a lot more exercise now," Lianne said.

"We're saving at least $150 a week and that's money the Government's not making on cigarettes."

Peter said it was not always just about overcoming nicotine addiction, because sometimes addicts needed to do something with their hands or "blow something out their mouths".

"In England, obviously, the government there is promoting vaping as a way to cease smoking," he said.

"But here, it's crazy. Why doesn't the Government just tax e-cigarettes and get involved?"

Tax revenue to pass $12 billion

Federal revenue from tobacco products in 2016 was $9.8 billion, with a further $1.48 billion raised in GST.

Excise rates have since increased, with smokers paying 80 cents in tax per cigarette and an estimated $12.5 billion to be raised in federal revenue this financial year.

How do e-cigarettes work?

E-cigarettes are battery-operated devices that heat a cartridge of liquid nicotine and flavour into a mist to be vaporised.

They deliver nicotine (the addictive agent in cigarettes) without burning tobacco and producing harmful smoke.

Smoking e-cigarettes is often referred to as vaping.

Population health specialist Professor Caroline Miller has worked for 20 years in tobacco control and advised state and federal governments on policy and programs.

She said she had never seen anything to suggest revenue raised from tobacco in Australia had influenced government decisions on vaping policy.

"The only discussion I have ever heard has related to concern about unknown effects of vaping, inadequacy of evidence of efficacy as a quitting aid, and potential for unintended consequences for loss of substantial progress in smoking cessation and prevention.

"For me, it is a question of promise and potential versus weight of evidence.

"If e-cigarettes are an efficacious cessation device, as people assert, then that evidence needs to be presented to the TGA so that those therapeutic claims can be verified."

Professor Miller said she supported Australia's oppositional stance to vaping and said it was based on summaries of best available evidence at the time, pointing out that using it as a device for harm reduction "is more widely supported by health agencies in the UK than in most other countries".

Policy makers 'missing the point'

But Savvas Dimitriou, chairman of Australian Vaping Advocacy Trade and Research who recently led a protest to the SA Parliament, said policy makers had missed the point.

"If you had the option between vaping and not vaping, then obviously not vaping is going to be better for you — but that's not what the question is," he said.

"The question is, is it better to smoke than to vape?

"It's tobacco harm reduction and that's the key piece of the puzzle the health bodies in Australia are missing."

PHE advised public hospitals in the UK to make e-cigarettes available to patients who are smokers, while vaping itself was being promoted by government agencies as a 95 per cent safer alternative to smoking, based on current knowledge.

"And yet here in Australia, most of our public health bodies have demonised vaping and are doing their level best to essentially have a ban," Mr Dimitriou said.

Precautionary approach required as research continues

A spokeswoman for Drug and Alcohol Services SA (DASSA) said the Commonwealth was funding a range of independent research into the health effects and potential benefits of e-cigarettes and the SA Government would continue to monitor research in the area.

She cited researchers who'd found that some flavourings could be toxic and should be reconsidered to make vaping safer, and that vaping itself was not risk free to non-smokers.

"National and international evidence supports the regulation of e-cigarettes, with the National Health and Medical Research Council's (NHMRC) 2017 review concluding health authorities should minimise harm and protect young people until there has been further research into the effects of e-cigarettes."

The spokeswoman also pointed to a CSIRO August report which found regular use of e-cigarettes was likely to have adverse health consequences.

That same report, however, also pointed out there was a lack of "clarity about the magnitude of adverse health effects and quantity of e-cigarette use required to trigger" them.

It found there was "evidence for improvement in individual health" in smokers who had switched to vaping "probably mainly due to the reduction in smoking", but also found e-cigarettes could introduce independent health risks.

"Based on the current evidence it is not possible to ascertain whether e-cigarettes have a positive or a negative effect on health in countries where they are permitted," the report's summary said.

SA traders consider moving interstate

Mr Dimitriou said SA's decision to categorise vaping products with tobacco products went further than any other jurisdiction in Australia and would only serve to send jobs and investment elsewhere.

He further questioned how the state could legally enforce others from selling into its jurisdiction.

For Ms Butcher, however, who spent $100,000 setting up her Vape 98 store and was in the process of establishing a second when the laws were changed, she said her biggest concern was what to do next as vape traders considered moving interstate.

The DASSA spokeswoman said the new laws were likely to begin in the first quarter of 2019 but that traders would have six months to make the transition.

"Given the lack of evidence about the safety and potential for health risks of e-cigarettes, the new laws take a precautionary approach aiming to protect the health of the community, including children, while still allowing adults to access these products," she said.

"[And] people living in regional and remote areas will be able to purchase e-cigarette products from a physical shop in the same way that tobacco products are purchased."